Blue Sea Systems
Marine circuit protection, fuse holders, battery switches, busbars, and electrical distribution components designed for dependable boat systems.
Blue Sea Systems develops dependable AC and DC electrical products for marine and specialized vehicle applications. The brand is known for practical solutions across circuit protection, power distribution, switching, and system monitoring. The Common Ground Marine selection currently focuses on Blue Sea Systems marine fuses and fuse holders, including ANL, MEGA, MAXI, Class T, and MRBF formats. Compare voltage, amperage, fuse style, and holder compatibility to protect the complete electrical circuit.
Products from Blue Sea Systems
206 products
Blue Sea SystemsBlue Sea Systems DC Digital Voltmeter 0 to 60V DC
DC digital voltmeter, 0-60V DC display range, splashproof front panel. Surface mounts in a 2in round hole. Applicable for 12-42V DC systems.
SKU BLUE-8235
$183.40MSRP $220.08
Blue Sea SystemsBlue Sea Systems DC Shunt 500A / 50mV
DC current shunt, 500A / 50mV, installs in the negative circuit for accurate DC ammeter readings. Two sense-lead screw terminals, not for carrying load current.
SKU BLUE-8255
$65.10MSRP $78.12
Blue Sea SystemsBlue Sea Systems Dash Socket 12V DC with Watertight Cap
12V DC dash socket, 15A maximum rating, watertight cap included, mounts in a 1-1/8in hole. Accepts any standard cigarette-lighter-style plugs.
SKU BLUE-1011
$10.50MSRP $12.60
Blue Sea SystemsBlue Sea Systems DeckHand Dimmer 12V DC 12A
DeckHand Dimmer, 12V DC, 12A rating. Smoothly controls brightness on incandescent or dimmable LED lighting circuits. Panel or surface mount installation.
SKU BLUE-7507B
$63.02MSRP $75.62
Blue Sea SystemsBlue Sea Systems DeckHand Dimmer 12V DC 6A
DeckHand Dimmer, 12V DC, 6A rating. Smoothly controls brightness on incandescent or dimmable LED lighting circuits. Panel or surface mount installation.
SKU BLUE-7506B
$54.30MSRP $65.16
Blue Sea SystemsBlue Sea Systems DeckHand Dimmer 24V DC 6A
DeckHand Dimmer, 24V DC, 6A rating. Smoothly controls brightness on incandescent or dimmable LED lighting circuits. Panel or surface mount installation.
SKU BLUE-7504B
$63.02MSRP $75.62
Blue Sea SystemsBlue Sea Systems Deckhand Dimmer - 24V DC 12A
Deckhand Dimmer - 24V DC 12A. Illuminated exit with adjustable time delay. Digitally controls dimming of non-regulated LEDs, incandescent, and halogen lights.
SKU BLUE-7509
$96.60MSRP $115.92
Blue Sea SystemsBlue Sea Systems Dual MRBF Terminal Fuse Block 30-300A
Two-position MRBF fuse block, 300A / 58V DC max per position. Mounts on a single 3/8in terminal stud. MRBF fuses sold separately, one per position.
SKU BLUE-2151
$39.20MSRP $47.04
Blue Sea SystemsBlue Sea Systems Dual PowerPost Two 3/8in-16 Studs
Dual PowerPost connector, Two 3/8"-16 studs, 48V DC maximum. Two independent stud terminals on one mount, with one black and one red insulator included.
SKU BLUE-2017
$20.30MSRP $24.36
Blue Sea SystemsBlue Sea Systems Dual PowerPost Two 5/16in-18 Studs
Dual PowerPost connector, two 5/16in-18 studs, 48V DC maximum. Two independent stud terminals on one mount, with black and red insulators included.
SKU BLUE-2016100B
$8.05MSRP $9.66
Blue Sea SystemsBlue Sea Systems DualBus 100A BusBar 5 Circuit
DualBus 100A busbar, 5 screw terminals per bus, positive and negative isolated on one compact block. Rated 100A continuous, 300V AC / 48V DC max.
SKU BLUE-2701
$25.20MSRP $30.24
Blue Sea SystemsBlue Sea Systems DualBus Plus 150A BusBar 1/4in-20 Stud 5 Gang
DualBus Plus 150A busbar, 5 screw terminals and 2 stud terminals per bus, positive and negative isolated on one block. Snap-on cover included.
SKU BLUE-2722
$26.60MSRP $31.92
Blue Sea SystemsBlue Sea Systems Fuse A3T / Class T 150 Amp
Fuse A3T / Class T 150 Amp. Extremely fast short-circuit response. 20,000 Ampere Interrupt Capacity (AIC).
SKU BLUE-5114
$58.10MSRP $69.72
Blue Sea SystemsBlue Sea Systems Fuse A3T / Class T 200 Amp
Fuse A3T / Class T 200 Amp. Extremely fast short-circuit response. 20,000 Ampere Interrupt Capacity (AIC).
SKU BLUE-200A
$58.10MSRP $69.72
Blue Sea SystemsBlue Sea Systems HD-Series On-Off Battery Switch, Grey
HD-Series single-circuit On-Off battery switch, 500A continuous, 32V DC maximum. Disconnects one battery to one load group. Ignition protected.
SKU BLUE-3000
$91.70MSRP $110.04
Blue Sea SystemsBlue Sea Systems HD-Series Selector 3-Position Battery Switch with AFD
HD-Series 3-position selector battery switch, 500A continuous rating, 32V DC maximum voltage. Includes AFD. Switches isolated battery banks to all loads.
SKU BLUE-11003
$96.60MSRP $115.92
Blue Sea SystemsBlue Sea Systems HD-Series Selector 4-Position Battery Switch without AFD
HD-Series 4-position selector battery switch, 500A continuous rating, 32V DC maximum voltage. No AFD included. Switches isolated battery banks to all loads.
SKU BLUE-3002
$116.20MSRP $139.44
Blue Sea SystemsBlue Sea Systems LED - 12/24V DC Amber
LED - 12/24V DC Amber. Easily installed in any Blue Sea Systems circuit breaker panel. Simple push-in installation mounts in any thickness material.
SKU BLUE-8033
$3.50MSRP $4.20
Blue Sea SystemsBlue Sea Systems LED - 12/24V DC Green
LED - 12/24V DC Green. Easily installed in any Blue Sea Systems circuit breaker panel. Simple push-in installation mounts in any thickness material.
SKU BLUE-8172
$3.50MSRP $4.20
Blue Sea SystemsBlue Sea Systems LED - 12/24V DC Red
LED - 12/24V DC Red. Easily installed in any Blue Sea Systems circuit breaker panel. Simple push-in installation mounts in any thickness material.
SKU BLUE-8171B-BSS
$2.57MSRP $3.08
Blue Sea SystemsBlue Sea Systems LED - 230V AC Green
LED - 230V AC Green. Easily installed in any Blue Sea Systems circuit breaker panel. Simple push-in installation mounts in any thickness material.
SKU BLUE-8134
$3.50MSRP $4.20
Blue Sea SystemsBlue Sea Systems Lockout Slide, 2 Position, 2 Pole
Lockout Slide, 2 position, 2 pole, for AC double-pole circuit breakers. Prevents mixing multiple AC power sources. Mounting screws included.
SKU BLUE-4125B
$14.70MSRP $17.64
Blue Sea SystemsBlue Sea Systems Lockout Slide, 3 Position, 2 Pole
Lockout Slide, 3 position, 2 pole, for AC double-pole circuit breakers. Prevents mixing multiple AC power sources. Mounting screws included.
SKU BLUE-4126B
$18.90MSRP $22.68
Blue Sea SystemsBlue Sea Systems M-Series Battery Switch Spare Key - Red
Spare red key for Blue Sea Systems' M-Series Mini On-Off Battery Switch with Key (PN 6005). Replaces a lost, damaged, or missing original key.
SKU BLUE-7900
$5.60MSRP $6.72
Choose the right Blue Sea Systems fuse
Start with system voltage, expected continuous current, conductor size, and the manufacturer's specified overcurrent protection. Then select the fuse family, amp rating, and a compatible holder or terminal block. Match the fuse to the holder and confirm the available interrupt rating and installation clearances.
Browse circuit protectionMarine circuit protection starts with the whole DC system
Blue Sea Systems offers several fuse formats for different installation and service requirements. Compare the electrical specification, physical format, and mating holder before ordering a replacement or building a new system.
- ANL, MEGA, MAXI, Class T, and MRBF fuse formats
- Fuse holders and terminal solutions for organized power distribution
- Guidance on voltage, amperage, conductor sizing, and compatibility
Frequently asked questions
What does Blue Sea Systems make?
Blue Sea Systems designs AC and DC electrical products for marine and specialized vehicle applications. The current selection includes marine fuses and a fuse holder for circuit protection and power distribution.
How do I choose a Blue Sea Systems marine fuse?
Confirm the system voltage, required amperage, conductor size, fuse type, holder compatibility, and the protection requirements specified by the equipment manufacturer. The fuse must be appropriate for the complete circuit, not just the load.
What is the difference between ANL, MEGA, MAXI, Class T, and MRBF fuses?
These are different fuse formats with different physical sizes, holders, ratings, and installation requirements. Use the product documentation and your system design to select the correct format and verify that the fuse and holder are a compatible pair.
Need a quote on Blue Sea Systems gear?
Tell us what you're building. Our team will spec the right kit for your install and send a written quote.
Why buy from us
We carry this brand because it earns its place on the boat.
Stocked for marine builds
We focus on parts that meet the conditions boats see — not just whatever ships fastest.
Engineering review on request
Send a parts list or a layout and we'll check it against your boat before you order.
Direct from our team
Pricing, availability, and product questions all go through the same people who build custom harnesses and panels.